Do central vestibular findings predict abnormal findings on magnetic resonance imaging?

OBJECTIVE: To determine whether central findings from vestibular tests predict abnormal findings on magnetic resonance imaging. METHOD: This study was a retrospective case series at a tertiary referral centre. The main outcome measure of this diagnostic intervention study was the positive predictive value of central vestibular findings in relation to magnetic resonance imaging abnormalities. RESULTS: Central vestibular findings had a 50.9 per cent positive predictive value for magnetic resonance imaging abnormalities across all age groups although they varied according to age group. Optokinetic nystagmus (p < 0.05) and abnormal findings on videonystagmography tests (p < 0.05) were the main predictors of magnetic resonance imaging abnormalities. White matter lesions constituted the bulk of the central lesions on magnetic resonance imaging followed by cortical and cerebellar atrophy. CONCLUSION: Central vestibular findings had a 50.9 per cent positive predictive value for magnetic resonance imaging abnormalities across all age groups. Magnetic resonance imaging is medically justified to further evaluate patients with central findings on vestibular studies. Therefore, it is reasonable to request magnetic resonance imaging in these patients.

Non-contrast magnetic resonance imaging for monitoring patients with acoustic neuroma.

OBJECTIVE: To assess the feasibility of non-contrast T2-weighted magnetic resonance imaging as compared to T1-weighted post-contrast magnetic resonance imaging for detecting acoustic neuroma growth. METHODS: Adult patients with acoustic neuroma who underwent at least three magnetic resonance imaging scans of the internal auditory canals with and without contrast in the past nine years were identified. T1- and T2-weighted images were reviewed by three neuroradiologists, and tumour size was measured. Accuracy of the measurements on T2-weighted images was defined as a difference of less than or equal to 2 mm from the measurement on T1-weighted images. RESULTS: A total of 107 magnetic resonance imaging scans of 26 patients were reviewed. Measurements on T2-weighted magnetic resonance imaging scans were 88 per cent accurate. Measurements on T2-weighted images differed from measurements on T1-weighted images by an average of 1.27 mm, or 10.4 per cent of the total size. The specificity of T2-weighted images was 88.2 per cent and the sensitivity was 77.8 per cent. CONCLUSION: The T2-weighted sequences are fairly accurate in measuring acoustic neuroma size and identifying growth if one keeps in mind the caveats associated with the tumour characteristics or location.

Epitope mapping of inhibitory antibodies targeting the C2 domain of coagulation factor VIII by hydrogen-deuterium exchange mass spectrometry.

BACKGROUND: The development of anti-factor VIII antibodies (inhibitors) is a significant complication in the management of patients with hemophilia A, leading to significant increases in morbidity and treatment cost. Using a panel of mAbs against different epitopes on FVIII, we have recently shown that epitope specificity, inhibitor kinetics and time to maximum inhibition are more important than inhibitor titer in predicting responses to FVIII and the combination of FVIII and recombinant FVIIa. In particular, a subset of high-titer inhibitors responded to high-dose FVIII, which would not be predicted on the basis of their inhibitor titer alone. Thus, the ability to quickly map the epitope spectrum of patient plasma with a clinically feasible assay may fundamentally change how clinicians approach the treatment of high-titer inhibitor patients. OBJECTIVES: To map the epitopes of anti-FVIII mAbs, three of which are classic inhibitors and one of which is a non-classic inhibitor, by the use of hydrogen-deuterium exchange coupled with mass spectrometry (HDX-MS). METHODS: The binding epitopes of four mAbs targeting the FVIII C2 domain were mapped with HDX-MS. RESULTS: The epitopes determined with HDX-MS are consistent with those obtained earlier through structural characterization and antibody competition assays. In addition, classic and non-classic inhibitor epitopes could be distinguished by the use of a limited subset of C2 domain-derived peptic fragments. CONCLUSION: Our results demonstrate the effectiveness and robustness of the HDX-MS method for epitope mapping, and suggest a potential role of rapid mapping of FVIII inhibitor epitopes in facilitating individualized treatment of inhibitor patients.

Guillain-Barré syndrome following severe head trauma and spine surgery.

Guillain-Barré syndrome (GBS) is an acute-onset inflammatory polyradiculoneuropathy usually triggered by an infectious disease. In some cases, GBS can occur without any preceding infectious episode, like after vaccination, epidural anaesthesia or surgery. A 73 years old woman had head and spine trauma. Body-TDM showed bilateral temporal and right frontal haematomas and fracture of the first lumbar vertebrae. Sextant and kyphoplasty were performed. She presented 14 days after surgery tetraparesis, swallowing difficulties and bilateral facial palsy. Electromyography was consistent with demyelinating neuropathy. Cerebrospinal fluid examination found albumino-cytological dissociation. Viral and bacterial serology and antiganglioside antibodies were negative. She was treated with intravenous immunoglobulins. Four months after discharge she had fully recovered except left peripheral facial palsy. GBS can rarely be triggered by head trauma or spine surgery. Physician must keep in mind this diagnosis whenever their patients present acute-onset neurological worsening in such context.

[Successful treatment with rituximab in a refractory Stiff-person syndrome]. / Efficacité du rituximab dans le traitement d'un Syndrome de Stiff person réfractaire.

Stiff person syndrome is a rare autoimmune disorder characterized by axial and limb progressive stiffness with surimposed spasms and production of autoantibodies to glutamic acid decarboxylase (GAD). We report a case of a 50-year-old woman who developed a stiff person syndrome resistant to conventional immunosuppressive treatments. Eight months after treatment, indexes of stiffness and spasm frequency improved, while however, the blood and CSF rates of anti-GAD increased. This observation illustrates the complexity of stiff person syndrome immunopathogenesis as well as the relevance of rituximab in this indication.

Tissue engineering in the twenty-first century.

In the 20th century, free tissue transfers have been successfully introduced using microvascular anastomosis techniques. Transplants not only include whole organs such as the kidney, liver and lung, but also bone, muscle and skin. However, there are a limited number of organs available for transplantation. This leads to the patient not only suffering from the malfunctioning tissue or organ, but also from the psychological trauma of an indefinite waiting period. The rapidly evolving field of tissue engineering is beginning to have an impact on free tissue transfers including organ. Small biopsy specimens can be grown into a large number of cells. These cultured cells can then be seeded onto biodegradable polymers, which serve several purposes. Firstly, the polymers function as a cell delivery system that enables the transplantation of a large numbers of cells into an organism. Secondly, they create a three-dimensional space for cell growth and serve as a template, thereby providing a structure for the extracellular matrix. These approaches have been demonstrated as practical strategies for the reconstruction of many tissues such as the liver, intestines, heart valve leaflets, bone and cartilage.